Based on the above, I believe hot scraping is the best if one has an iron and a nice garage-like place to do the waxing job. Some may not be lucky to have a nice space and time to do the waxing job, so a quick cleaner fits them well.
The purpose of cleaning is to clean the dirt/wax mixture on the base. Wax itself does not dissolve in detergent or water. Detergents mostly take away the surface dirt, not the mixed wax/dirt. Hot scraping does this job, because the prep wax attaches to the old wax so well. Base cleaners are chemically non-polar solvents which dissolve wax very well, so as to remove dirt. Fluorocarbon wax is much difficult to dissolve. Commercial fluoro wax cleaners contains some harsh solvents (also fluoro-based). It is definitely not good for health, unless you put on a mask or do it in a hood.
Cleaning with these kinds of solvent once a season does not give any side effect to you. Fluoro compounds does not poison human immediately, but the accumulated by-product from metabolism does (don't worry, it may take 20 or 30 years to be effective).
As a chemist, I've inhaled enough chemicals. I personally don't wanna more in my life. There might be some people, like me, don't wanna use chemical solvents either.
Thus, my friends (also chemists and skiers) and me started a company in New York, developed all natural, bio-based prewax&cleaners for skiers and snowboarders:
The cleaner does not only remove dirt/old wax, but also conditions the base (no dry-out worries) for waxing. It contains fresh micro particulate wax that replaces the old wax.
I am not selling it here, but would like to invite friends who have the chemical concerns to try. Please send me a message or like our facebook page: https://www.facebook.com/KaepsSports
I am more than happy to send you a fee sample to try and see how it works on your boards. To see is to believe.